Project Summary. The Polyamines Gordon Research Conference (GRC) has run continuously since 1975, and provides a multidisciplinary forum that brings together leading polyamine researchers, as well as young and established investigators new to the field. The 2019 Polyamines GRC will be held at Waterville Valley Hotel in Waterville Valley, NH, from June 23-28, 2019. This GRC will have a broad focus on the role of polyamines in human diseases, with topic areas that include cancer biology, immunology/inflammation, host-pathogen interactions, digestive diseases, diabetes, neurologic disorders, and many new potential interventions. The meeting is unique in that it attracts a diverse array of top investigators assessing the control and roles of polyamines across a broad spectrum of model systems (prokaryotes, parasites, Drosophila, plants, vertebrates, and mammals). Polyamines are small, amino-acid-derived polycations found in all forms of life and play essential roles in many cellular processes, including transcription, translation, replication, metabolism, epigenetic control, and ion channel functions. The 2019 Polyamines GRC will emphasize targeting polyamine pathways in cancer and other diseases. It will showcase key new links between arginine metabolism and polyamines, and other metabolic control pathways that can then lead to alterations in host defense against pathogens and tumors, immune responses leading to inflammation, carcinogenesis, metabolic disorders, neurologic diseases, aging, and the microbiome. The Program has a strong mix of basic, translational, and clinical researchers. This GRC is attended by biologists, chemists, and physician-scientists, and includes investigators from academia, biotech, and pharmaceutical sectors. The diversity of scientific disciplines is unique among GRCs, is highly stimulating, and will emphasize new findings relating to upstream and downstream pathways, and diseases only recently linked to alterations in polyamine biology. We will bring the latest studies, new investigators to the field, and early career investigators to this forum. Of the 26 named speakers, 25 are new since the last GRC and 18 have never spoken at the GRC; 9 are early career scientists. We will choose 6 speakers from the Gordon Research Seminar (GRS) and the posters, which will add more new speakers. The specific aims seek to obtain funds to support 41 GRC and 16 GRS registrations, and travel costs for 16 GRC/GRS participants. The long-term objective is to enhance understanding of the interplay between polyamine metabolism and human diseases, and to develop promising young scientists into contributing members of the polyamine scientific community. Presentations by invited speakers will be 25-30 minutes, with a 10-minute discussion. The GRC will be held in conjunction with the 7th Polyamines GRS, providing graduate students and fellows with a student-run venue that fosters exchange of data and ideas. The GRS makes the GRC a richer experience, promoting participation of young scientists during the main conference. Interactions between GRS and GRC conferees facilitate sharing of new ideas and create new partnerships that will drive the field forward.